| Lat / long: | 18.24455, -66.79947 |
| Primary: | Copper, Gold, Silver |
| Ore: | Chalcopyrite |
| Gangue: | Anhydrite |
| Other material: | Magnetite, Pyrite |
| Discovery year: | 1958 |
| Operation type: | Unknown |
| Production size: | None |
| Development status: | Occurrence |
| Host type: | Felsic Volcanic Rock,Basalt |
| Associated type: | Tonalite |
| Structure: | Pluton Is In Elongate Cluster Of Stocks Aligned Perpendicular To The Regional Grain Of The Island. Fractures Striking N.18 W. And N.2 E. In The Helecho Porphyry Match Mineralized Fractures In The Tanama Deposit. The N.30 E.-Striking Fractures Match The Trend Of The Elongate Cluster Of Stocks Of Which Helecho And Tanama Are A Part., Veins And Mineralized Fractures Show Difference In Orientation Between The Porphyry And Metavolcanic Country Rocks. N.30 E.-Striking Fractures Predominate In The Volcanic Rocks But Are Rare In The Porphyry. |
| Tectonic: | Gold-Rich Porphyry System In Low-Potassium Island Arc Environment |
| Alteration processes: | Chalcopyrite Associated With Magnetite In Feldspar-Stable-Alteration Assemblages, And With Pyrite In The Feldspar-Destructive-Alteration Zone |
| MRDS | W701059 |
| DEP | 10085468 |
| Reference | {Deposit:: COX, DENNIS P., AND BRIGGS, REGINALD P., 1973, METALLOGENIC MAP OF PUERTO RICO: U.S. GEOLOGICAL SURVEY, MISCELLANEOUS GEOLOGIC INVESTIGATIONS MAP I-721, ACCOMPANIED BY EXPLANATORY PAMPHLET, 6 P.}{Deposit:: COX, DENNIS P., 1985, GEOLOGY OF THE TANAMA AND HELECHO PORPHYRY COPPER DEPOSITS AND VICINITY, PUERTO RICO: U.S. GEOLOGICAL SURVEY PROF. PAPER 1327, 59 P.}{Deposit:: BARABAS, A. H., AND QUINN, E. J., 1980, ALTERATION, MINERALIZATION, AND FLUID INCLUSIONS IN THE HELECHO PORPHYRY COPPER PROSPECT, WEST CENTRAL PUERTO RICO [ABST.]: 9TH CARIBBEAN GEOL. CONF. SANTO DOMINGO TRANS., P. 2-3.} |
| Reporter | Paidakovich, Matthew E. |